Has anyone safely removed a Cooke f2.5 from a Graflex Series C? Mine's been in place forever, and I need to get inside to clean the mirror etc.? Where do you safely grip? - how hard can you turn without damaging? Does the f-stop dial unscrew too? Any help would be welcome.

The achilles heel to the C is the mount the lens is in. It has a tendency to expand over decades and freeze both the lens to the board and the aperture dial in the last position it was in.

Oh and as it ages it gets brittle.

So the answer to "how hard can I wrench" is "not much"

And it doesn't tell you before hand what is too much. You can go from a nice camera with a dirty mirror to a hand full of broken aluminum and glass faster than you can say Oh S***!

The limit of force i'd put on it is what I could do with rubber gloves over my hand and maybe somebody else holding the body of the camera. If it doesn't budge, then it never will.

I've not had the pleasure of owning a C, but with some diligence I've been able to remove the ground glass on my Press Graflex. I think it's best if you tried to clean the mirror through the top rather than risk shattering the lens mount.

Les

_________________"In order to invent, you need a good imagination and a lot of junk" Thomas Edison

Les is right, the safest way is to clean the mirror is thru the top! The GG is easily removed! Leave the mirror in the up position, and support it thru the back with your hand! Carefull with the cleaning, as some mirrors have the coating on the top!
.....Bert

Thanks to both. As it happens I may have been VERY lucky! With patience and gentle persuasion the lens came out with no problems, and now screws in and out smoothly. The aperture ring is also fine. I guess regular careful use is the best protection against seizing up? Incidentally - the results from this lens are simply extraordinary - by any modern standard. Beautiful fully open, but pin sharp edge to edge stopped down, and contrasty with colour film. Seems to break all the rules we believe about coatings and progress....!